/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.coders;



import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.math.BigInteger;



import static com.bff.gaia.unified.vendor.guava.com.google.common.base.Preconditions.checkNotNull;



/**

 * A {@link BigIntegerCoder} encodes a {@link BigInteger} as a byte array containing the big endian

 * two's-complement representation, encoded via {@link ByteArrayCoder}.

 */

public class BigIntegerCoder extends AtomicCoder<BigInteger> {



  public static BigIntegerCoder of() {

    return INSTANCE;

  }



  /////////////////////////////////////////////////////////////////////////////



  private static final BigIntegerCoder INSTANCE = new BigIntegerCoder();

  private static final ByteArrayCoder BYTE_ARRAY_CODER = ByteArrayCoder.of();



  private BigIntegerCoder() {}



  @Override

  public void encode(BigInteger value, OutputStream outStream) throws IOException, CoderException {

    encode(value, outStream, Context.NESTED);

  }



  @Override

  public void encode(BigInteger value, OutputStream outStream, Context context)

      throws IOException, CoderException {

    checkNotNull(value, String.format("cannot encode a null %s", BigInteger.class.getSimpleName()));

    BYTE_ARRAY_CODER.encode(value.toByteArray(), outStream, context);

  }



  @Override

  public BigInteger decode(InputStream inStream) throws IOException, CoderException {

    return decode(inStream, Context.NESTED);

  }



  @Override

  public BigInteger decode(InputStream inStream, Context context)

      throws IOException, CoderException {

    return new BigInteger(BYTE_ARRAY_CODER.decode(inStream, context));

  }



  @Override

  public void verifyDeterministic() {

    BYTE_ARRAY_CODER.verifyDeterministic();

  }



  /**

   * {@inheritDoc}

   *

   * @return {@code true}. This coder is injective.

   */

  @Override

  public boolean consistentWithEquals() {

    return true;

  }



  /**

   * {@inheritDoc}

   *

   * @return {@code true}, because {@link #getEncodedElementByteSize} runs in constant time.

   */

  @Override

  public boolean isRegisterByteSizeObserverCheap(BigInteger value) {

    return true;

  }



  /**

   * {@inheritDoc}

   *

   * @return the size of the encoding as a byte array according to {@link ByteArrayCoder}

   */

  @Override

  protected long getEncodedElementByteSize(BigInteger value) throws Exception {

    checkNotNull(value, String.format("cannot encode a null %s", BigInteger.class.getSimpleName()));

    return BYTE_ARRAY_CODER.getEncodedElementByteSize(value.toByteArray());

  }

}